BOM Template & Guide
Give every component line a clear part identity, quantity and population decision.
One consistent file set, with a clear revision.
Include any questions for your project contact.
Make every BOM line purchasable and traceable
A list of component values is not a controlled purchasing BOM.
The BOM connects part identification to reference designators. Manufacturer part numbers, descriptions and package information are common inputs, but each receiving system can require a different column schema. The template below is a proposed preparation format, not an industry-mandated header set.
| Field | Meaning in this template | Example / format | Review rule |
|---|---|---|---|
| Designators | The component positions grouped by this line | R1,R2 | List individual references; explain any non-PCB items separately. |
| QtyPerBoard | Number of listed positions on one board before populate status | 2 for R1,R2 | In this template, a DNP row may still list its design-position count. |
| Manufacturer + MPN | The approved manufacturer and one exact primary part | Use the released part identifier | Place alternatives in a separate controlled field. |
| Value / description | Electrical and functional requirements | Resistance / capacitance, tolerance, ratings, function | Do not assume value alone fully identifies a purchasable part. |
| Package / footprint | Physical package and, where relevant, footprint identity | 0603 imperial / 1608 metric | State the naming convention; verify the actual land pattern. |
| Populate | FIT or DNP for the selected variant | FIT | Do not mix FIT and DNP positions in one grouped row. |
| Supply | Who provides the part | Turnkey / Consigned | Keep sourcing responsibility separate from quantity demand. |
| ApprovedAlternates | Explicitly approved substitutions or an approval reference | Separate from primary MPN | Do not silently treat an alternative as pre-approved. |
| Variant / notes | Configuration and additional controlled instructions | Variant-A | Avoid conflicting free-text instructions. |
Keep per-board demand separate from purchase quantity
Do not multiply quantities by panel count unless that is the agreed unit basis.
| Illustrative line | Designators | QtyPerBoard | Populate | Installed on 100 boards |
|---|---|---|---|---|
| Same approved resistor | R1,R2 | 2 | FIT | 200 |
| Approved capacitor | C1 | 1 | FIT | 100 |
| Optional resistor position | R3 | 1 | DNP | 0 |
Fitted batch demand = QtyPerBoard × assembled board quantity. A DNP line installs zero components. This calculation excludes setup allowance, attrition, package rounding, minimum order quantity and any agreed spares.
Group only positions that share the same approved part, populate state, variant and sourcing instructions. Two components with the same value may require different ratings, packages or manufacturer parts.
Prepare the purchasing data without losing meaning
- 01
Export the selected configuration
Start from the released CAD or controlled parts database. Select the intended assembly variant and keep its revision visible.
- 02
Identify the exact primary part
Record manufacturer and complete MPN, including relevant ordering suffixes. Keep supplier stock codes in separate notes or columns. Do not combine several alternatives in the primary MPN field.
- 03
Reconcile the reference list
Expand grouped references, check duplicates and compare the fitted scope with the placement and assembly instructions. Document hand-fit and mechanical exceptions.
- 04
Preserve identifiers as text
When editing in a spreadsheet, import part numbers as text and verify that leading zeros, punctuation and long identifiers have not changed. Keep a clear machine-readable export without merged cells or decorative header rows.
- 05
Review substitutions and missing information
Record approved alternatives separately. Resolve missing manufacturer / part data or document a complete approved generic specification and purchasing authorization.
- 06
Release the BOM with the rest of the package
Match the PCB revision and assembly variant. Have the responsible engineer or buyer approve the sourcing and population decisions before production release.
Review the BOM alongside the board
Review purchasing identity, population and physical fit as separate checks.
Missing parts are decisions—not blanks
A blank MPN is not permission to source an arbitrary equivalent. Clarify whether the item is DNP, consigned, a mechanical item, or a part requiring additional specification.
DNP should be machine-readable
Use the dedicated Populate field and corresponding variant instructions. Do not rely only on color, strikethrough or a note that an importer may ignore.
Generic parts need approved requirements
Where generic sourcing is permitted, define the full relevant specification and the scope of substitution authority. Do not use “10 k resistor” as the entire requirement.
Supplier information is not manufacturing intent
Availability, pricing, pack sizes and sourcing routes need confirmation. The BOM identifies the approved part and population, not an unconditional delivery promise.
Download the preparation files
Download the checklists and templates below without signing in or submitting a form.
PCB & PCBA workbook
Eight sheets: instructions, BOM and placement inputs/examples, RFQ review and batch arithmetic.
XLSX · 19.5 KBBlank BOM template
Header-only UTF-8 CSV. Add released purchasing data; no demonstration parts included.
CSV · 0.1 KBBOM example — not for purchase
Shows grouped designators, per-board quantities and DNP treatment using placeholder MPNs.
CSV · 0.7 KBRead before using the templates
Field definitions, limitations and release-control notes.
TXT · 3.5 KBFrequently asked questions
Can I group R1,R2 on one line?
Yes, in this preparation template, when both references use the same approved part, populate status, variant and sourcing instruction. QtyPerBoard is then 2. Confirm that the receiver supports your designator separator.
Can I use only a supplier stock number?
Provide the approved manufacturer and exact manufacturer part number where applicable. A supplier code is useful supporting information, but should not make the approved part identity ambiguous.
Should DNP components be removed entirely?
Use the agreed variant policy. This template keeps explicit DNP rows so the decision is visible; the production placement export may exclude them. Reconcile the selected policy across all documents.
Does the batch planner calculate purchasing overage?
No. It multiplies fitted per-board positions by board quantity and sets DNP demand to zero. Setup loss, extra material, pack quantities and purchasing constraints must be agreed separately.
Are the downloadable example part numbers real purchasing recommendations?
No. The examples deliberately use placeholder manufacturer / MPN entries and are labeled NOT FOR PURCHASE. Use the blank template for your released data.
Can the spreadsheet verify every part against its footprint?
No. It does not validate electrical suitability, sourcing status or physical land-pattern compatibility. Those remain engineering and purchasing review tasks.
Technical references & scope
- [10] KiCad — PCB Editor: Manufacturing Outputs and Design Rules
- [12] JLCPCB — BOM file guidance (its own intake requirements)
Use the checklists and templates on this page to prepare your manufacturing files. Confirm the required formats and approved design revision with your project contact before ordering; export steps may vary by CAD software.
File preparation resources for PCB & PCBA projects.